OG2.1,OG3.1,OG4.1,OG5.1-2,OG6.1,OG7.1 | Foundations of Reproduction and Pregnancy — Practice Quiz

Correct. The uterine artery crosses ABOVE the ureter at the level of the lateral cervix — remembered by 'water (ureter) under the bridge (uterine artery)'. Failure to identify this relationship is a major cause of iatrogenic ureteric injury during hysterectomy.

Uterine artery crosses the ureter at the lateral cervix — 'water under the bridge'. Ureteric injury is the most feared complication of this anatomical variant.

The key surgical relationship here is that the uterine artery passes above the ureter at the lateral cervix. This 'water under the bridge' mnemonic is essential for safe pelvic surgery.

Correct. The luteal phase is fixed at 14 days. Ovulation occurs 14 days BEFORE the next expected period. For a 35-day cycle: 35 − 14 = Day 21. The follicular phase is variable; only the luteal phase is constant.

Ovulation = cycle length minus 14 days. The luteal phase is fixed at 14 days; the follicular phase is variable. This is why timing-based contraception fails in irregular cycles.

Day 14 applies only to a 28-day cycle. The key principle: ovulation = cycle length minus 14. For a 35-day cycle, ovulation is on Day 21 because the luteal phase is always fixed at 14 days.

Correct. Rising oestradiol from the dominant follicle exerts a positive-feedback effect on the anterior pituitary, triggering the mid-cycle LH surge that causes ovulation approximately 36–44 hours later.

Sustained high oestradiol from the dominant Graafian follicle triggers the LH surge via positive feedback. Ovulation follows 36–44 hours after the LH surge peak.

Progesterone and inhibin B are mainly negative-feedback signals. The key pre-ovulatory signal is a sustained rise in oestradiol that switches from negative to positive feedback, triggering the LH surge.

Correct. Organogenesis — the formation of all major organ systems — occurs during embryonic weeks 3–8 (gestational weeks 5–10). This is the critical window for structural teratogenicity. Weeks 1–2 follow an 'all-or-nothing' principle.

Organogenesis: weeks 3–8 of embryonic life (gestational weeks 5–10). This is the critical teratogen window. Most women do not yet know they are pregnant during this period — underscoring the importance of preconception counselling.

Weeks 1–2 are the pre-embryonic 'all-or-nothing' period. The critical teratogen window for organogenesis is weeks 3–8. After week 8, the fetal period begins and damage tends to cause growth restriction rather than major structural defects.

Correct. HbF has a higher oxygen affinity than HbA because it has reduced binding to 2,3-DPG. This left-shifted oxygen dissociation curve allows HbF to load oxygen at the relatively low PO₂ (~30 mmHg) found on the fetal side of the placenta.

HbF has a left-shifted O₂ dissociation curve (higher affinity) due to less 2,3-DPG binding. Combined with the double Bohr effect at the placenta, this ensures adequate fetal oxygenation despite low PO₂ (~30 mmHg).

HbF's advantage is its LEFT-shifted oxygen dissociation curve (higher O₂ affinity), achieved by reduced 2,3-DPG binding. This allows efficient O₂ transfer at low placental PO₂. HbA has more 2,3-DPG binding and a right-shifted curve.

Correct. Optimising glycaemic control before conception (HbA1c target <6.5%, or <48 mmol/mol) reduces the risk of congenital malformations (cardiac, neural tube), miscarriage, and macrosomia. Insulin remains the safe agent in pregnancy; many oral hypoglycaemics are not recommended.

Pre-conception diabetes: target HbA1c <6.5% before attempting pregnancy. Insulin is the safe agent. Poor glycaemic control in the first 8 weeks (organogenesis) drives congenital malformations — especially cardiac defects and caudal regression syndrome.

Oral hypoglycaemics such as metformin are not recommended as a first-line switch preconception in T1DM. Insulin is safe in pregnancy. The key intervention is achieving HbA1c <6.5% before conception to minimise congenital malformations.

Correct. Rubella infection in the first trimester causes congenital rubella syndrome (cataracts, deafness, cardiac defects). Serology must confirm immunity; if non-immune, MMR (a live attenuated vaccine) should be given at least 1 month before conception. Live vaccines are contraindicated in pregnancy.

Preconception: check rubella immunity. If non-immune, give MMR at least 1 month before conception (live vaccine — contraindicated in pregnancy). Other preconception vaccines: varicella (if non-immune), Hepatitis B if at risk.

While Hepatitis B is important, the most critical preconception vaccine check is rubella immunity — because rubella in early pregnancy causes severe congenital defects. MMR is a live vaccine (contraindicated in pregnancy), so it must be given before conception.

Correct. An adnexal mass with positive beta-hCG and no intrauterine gestational sac on TVU (above the discriminatory zone of 1,500–2,000 mIU/mL) is an ectopic pregnancy until proven otherwise. Any woman of reproductive age with pelvic pain must have a pregnancy test first.

Any woman of reproductive age with pelvic pain or vaginal bleeding requires a pregnancy test before any other diagnosis. TVU discriminatory zone for beta-hCG is 1,500–2,000 mIU/mL. No IUP above this level = ectopic pregnancy until proven otherwise.

Above the discriminatory zone (1,500–2,000 mIU/mL for TVU), an intrauterine pregnancy should be visible. No IUP + adnexal mass + positive beta-hCG = ectopic pregnancy until proven otherwise. This is a surgical emergency — do not delay.

Correct. Positive signs of pregnancy are those that cannot be due to any other condition: fetal heart sounds (auscultated), fetal movements felt by the examiner, and visualisation of fetus on ultrasound. Hegar's sign is probable; amenorrhoea and nausea are presumptive; urine hCG is probable.

Three-tier classification: Presumptive (amenorrhoea, nausea, quickening by mother), Probable (Hegar's sign, positive hCG test, uterine enlargement), Positive (fetal heart sounds on auscultation, ultrasound visualisation, fetal movements felt by examiner).

Positive signs = cannot be due to any other cause: auscultated fetal heart sounds, fetal parts felt by examiner, ultrasound visualisation of fetus. A positive pregnancy test and Hegar's sign are 'probable' signs. Amenorrhoea is only 'presumptive'.

Correct. Greater plasma expansion than red cell mass expansion causes a dilutional fall in haemoglobin — physiological anaemia of pregnancy. Haemoglobin normally falls to approximately 10.5–11 g/dL at 28–34 weeks. Pregnancy is also a hypercoagulable state (clotting factors increase), not a hypocoagulable one.

Physiological anaemia of pregnancy: plasma volume +40–50% vs red cell mass +20–25% → dilutional fall in Hb. Normal Hb threshold: 11 g/dL in 1st/3rd trimester, 10.5 g/dL in 2nd trimester (WHO). Below these = true anaemia requiring investigation.

Since plasma expands more than red cells, haemoglobin concentration falls — this is physiological (dilutional) anaemia of pregnancy, NOT polycythaemia. Pregnancy also increases clotting factors (hypercoagulable state), not decreases them.